The embodiments discussed herein are related to a printer apparatus.

A printer apparatus for outputting a receipt or the like is widely used for various purposes such as a cashier terminal of a shop or an ATM (Automated Teller Machine) or a cash dispenser of a bank. For example, a printer apparatus outputs a receipt by printing characters or the like on a recording paper (e.g., heat sensitive paper) with a thermal head while conveying the recording paper.

When using the printer apparatus, characters or the like are printed on the recording paper by providing the recording paper between the thermal head and a platen roller. The platen roller is detachably attached to the printer apparatus, so that the recording paper can be easily provided between the thermal head and the platen roller.

Accordingly, the recording paper is sandwiched between the thermal head and the platen roller by pressing the thermal head toward a side in which the platen roller is provided. In this state where the recording paper is sandwiched between the thermal head and the platen roller, printing by the thermal head is performed.

Thus, typically, a biasing member (e.g., coil spring) is provided behind the thermal head. One end of the coil spring or the like contacts the thermal head whereas the other end of the coil spring or the like contacts a rear surface support plate. Thereby, a recovering force of the coil spring or the like causes pressure to be exerted to the thermal head in the direction toward the platen roller via the rear surface support plate.

Patent Document 2 discloses a lock arm that supports a bearing of a platen roller in which a position of the platen roller is defined by using a biasing force of a pressure spring exerting pressure to a thermal head. Patent Document 4 discloses a configuration that includes a first spring provided between a lock arm and a thermal head for biasing a platen roller in a direction toward the thermal head, and a second spring provided between the thermal head and a frame body for biasing the thermal head in a direction to contact the platen roller.

Patent Document 6 discloses an arrangement for a thermal printer.

• [Patent Document 1]: Japanese Patent No. 3734753
• [Patent Document 2]: Japanese Patent No. 3599595
• [Patent Document 3]: Japanese Laid-Open Patent Publication No. 2000-318260
• [Patent Document 4]: Japanese Laid-Open Patent No. 2008-68551
• [Patent Document 5]: Japanese Laid-Open Patent No. 2000-94767
• [Patent Document 6]: EP2070708A2

Typically, in a case of a thermal printer that prints characters or the like on a recording medium by using a thermal head, a platen roller is retained by a lock arm by way of, for example, a platen bearing formed of a mold resin or the like. The thermal printer that is used for various purposes may be accidentally dropped or applied with an unexpected amount of force when the thermal printer is being used. In this case, the platen bearing or other members of the platen roller may be damaged (malfunction) and become unusable if the platen roller cannot disengage from the thermal printer.

Specifically, in a case of, for example, a thermal printer that has a lock arm formed in its disengaging direction (removing direction) in a manner covering a large portion of the platen bearing or the like of the platen roller, the platen roller may not easily disengage from the thermal printer even if force is exerted to the thermal printer when the thermal printer is dropped. Thus, if the platen roller cannot disengage from the thermal printer, the platen bearing or the like could be damaged by the impact caused when, for example, the thermal printer is dropped. As a result, the thermal printer can no longer be used.

According to an embodiment of the present invention, it is an object to provide a printer apparatus that is resistant to damage even in a case where, for example, impact is applied to the printer apparatus when the printer apparatus is dropped. Means for solving problem

According to an aspect of the invention, there is provided a printer apparatus according to claim 1.

According to an embodiment of the present invention, there can be provided a printer apparatus that can be steadily used for a long period owing to its resistance to damage even in a case where, for example, impact is applied to the printer apparatus when the printer apparatus is dropped.

• Fig. 1 is a perspective view of a printer apparatus according to an embodiment of the present invention;
• Fig. 2 is an explanatory diagram of the printer apparatus of the embodiment observed diagonally (1);
• Fig. 3 is an explanatory diagram of the printer apparatus of the embodiment observed diagonally (2);
• Fig. 4 is an explanatory diagram of the printer apparatus of the embodiment observed from its side;
• Fig. 5 is an enlarged partial view of Fig. 4;
• Fig. 6 is an explanatory diagram of a frame 160;
• Fig. 7 is an explanatory diagram of an opening/closing arm 130;
• Fig. 8 is an explanatory diagram of a contact point 136a between the opening/closing arm 130 and a platen bearing 121;
• Fig. 9 is an explanatory diagram of force exerted to the contact point 136a;
• Fig. 10 is an explanatory diagram in a case where a platen roller 120 is disengaged;
• Fig. 11 is an explanatory diagram of a projecting part 138 provided in the opening/closing arm 130 (1);
• Fig. 12 is an explanatory diagram of the projecting part 138 provided in the opening/closing arm 130 (2);
• Fig. 13 is an explanatory diagram of the printer apparatus of the embodiment (1);
• Fig. 14 is an explanatory diagram of the printer apparatus of the embodiment (2);
• Fig. 15 is an explanatory diagram of the printer apparatus of the embodiment (3); and
• Fig. 16 is an explanatory diagram of the printer apparatus of the embodiment (4).

In the following, embodiments of the present invention are described with reference to the accompanying drawings. Like components are denoted with like reference numerals and are not further explained.

A printer apparatus according to an embodiment is described with reference to Figs. 1-3. Fig. 1 is a perspective view of a printer apparatus according to the embodiment, Fig. 2 is a perspective view illustrating the printer apparatus viewed from another angle in a state a housing cover is attached to the printer apparatus, and Fig. 3 is a perspective view illustrating the printer apparatus from the same angle as Fig. 2 in a state where a gear part 180 and other elements are removed from the printer apparatus. As illustrated in Figs. 1-3, the printer apparatus of the embodiment includes a thermal head 110 which is a printer head, a platen roller 120, an opening/closing arm 130, a first biasing spring 140, and a second biasing spring 150. The thermal head 110, the platen roller 120, the opening/closing arm 130, the first biasing spring 140, and the second biasing spring 150 are mounted to the frame 160. In the printer apparatus of the embodiment, the platen roller 120 is supported by the frame 160 by force exerted from the first biasing spring 140. In this embodiment, a coil spring, a leaf spring or the like may be used as the first biasing spring 140, and a torsion spring or the like may be used as the second biasing spring.

A platen bearing 121 of the platen roller 120 is rotatably supported by a frame side 161 of the frame 160. A motor 170 for rotating the platen roller 120 is provided to the frame 160. By rotating the motor 170, the platen roller 120 is rotated via the gear part 180.

A heat sink 111 corresponding to a head support plate is provided to a rear surface of the thermal head 110. The frame 160 includes a frame rear surface part 162 facing the heat sink 111. The first biasing spring 140 such as a coil spring is provided between the heat sink 111 and the frame rear surface part 162 of the frame 160. The thermal head 110 is pressed toward a side in which the platen roller 120 is provided owing to a recovering force of the first biasing spring 140 transmitted via the heat sink 111.

The opening/closing arm 130 is supported by the frame side surface 161 to rotate and move about the arm rotation shaft 131. The second biasing spring 150 such as a torsion coil spring is provided between the opening/closing arm 130 and the frame side surface 161. Specifically, although not illustrated in the drawings, one end of the second biasing spring 150 is connected to the frame part 160 and the other end of the second biasing spring 150 is connected to the opening/closing arm 130. The opening/closing arm 130 can be rotated and moved about the arm rotation shaft 131 by pressing an opening/closing arm cap receiving part 134. By releasing the force exerted to the opening/closing arm cap receiving part 134, the opening/closing arm cap receiving part 134 moves upward by the recovering force of the second biasing spring 150. Thereby, the opening/closing arm 130 returns to its initial state.

Next, the frame 160 is described with reference to Figs. 4-6. Fig. 4 is a side view illustrating the printer apparatus of the embodiment, Fig. 5 is an enlarged view of a portion of Fig. 4, and Fig. 6 is a side view of the frame 160.

A frame opening part 162 into which the platen bearing 121 can be guided is provided in the frame side surface 161 of the frame 160 for supporting the platen roller 120. The frame opening 162 is formed in a U-shape. First guide part 163 and the second guide part 164 are formed at an inlet part of the frame opening part 162 for guiding the platen bearing 121 into the frame opening part 162. The first guide part 163 is formed on a side more toward the thermal head 110 (heat sink 111) than the second guide part 164. The first guide part 163 is formed longer than the second guide part 164. A line L1 extends along a straight edge part 163a formed in the frame opening part 162, and a line L2 extends along a straight edge part 164a formed in the frame opening part 162 are formed to be substantially parallel to each other. Further, the line L1 and the line L2 are formed in a direction that is substantially orthogonal to a direction of a recovery force of the first biasing member 140 of the embodiment. In the printer apparatus of the present invention, the platen bearing 121 is supported by contacting an insulating part 164a of the second guide part 164 by the recovering force of the first biasing spring 140. Therefore, the line L2 becomes a tangential line between the edge part 164a of the second guide part 164 and the platen bearing 121.

The edge part 164a of the second guide part 164 is formed on a line L3 that runs through a center 121a of the platen bearing 121. Alternatively, the edge part 164a of the second guide part 164 may be formed above the line L3 in the drawing. In the second guide part 164 of the printer apparatus according to this embodiment, the straight edge part 164a overlapping the line L2 may be formed to have a length of approximately 0.2 mm.

Next, the opening/closing arm 130 is described with reference to Figs. 4, 5, and 7. The opening/closing arm 130 is rotated and moved about the arm rotation shaft 131 by pressing the opening/closing arm cap receiving part 134. An opening/closing arm opening part 135 into which the platen bearing 121 of the platen roller 120 is inserted is provided in an opening/closing arm side surface. A lock part 136 is provided at a position that is the edge of the opening/closing arm opening part 135 and farthest from the arm rotation shaft 131. An outer contact part 137 for pressing out the platen bearing 121 during the below-described removal of the platen roller 120 is provided on the side opposite from the lock part 136 interposed by the opening/closing arm opening part 135. Fig. 7 is a side view of the opening/closing arm 130.

The platen bearing 121 of the platen roller 120 according to this embodiment is pressed by the recovering force of the first biasing spring 140 in the direction of the arrow A1 as illustrated in Fig. 4. Further, the frame 160 is pressed by the platen bearing 121 in the direction of the arrow B1 in Fig. 4. Accordingly, the platen bearing 121 is rotatably supported by the frame 160. That is, the platen bearing 121 is supported in a state provided in the opening/closing arm opening part 135 while being supported by the frame 160 with respect to the biasing direction of the recovering force of the first biasing spring 140 illustrated with the arrow A1. Accordingly, the platen bearing 121 does not contact the opening/closing arm 130 with respect to the direction illustrated with the arrow B1. Therefore, the platen bearing 121 is not supported by the opening/closing arm 130.

The platen bearing 121 contacts the lock part 131 of the opening/closing arm 130 at a contact point 136a, so that the platen bearing 121 can be prevented from moving in an upward/downward direction in Fig. 5. Accordingly, the lock part 136 does not support the platen bearing 121 with respect to the biasing direction of the recovering force of the first biasing spring 140 illustrated with the arrow A1 but is for preventing the platen bearing 121 from moving in a direction that is substantially orthogonal to the direction illustrated with the arrow A1.

Next, a relationship between the opening/closing arm 130 and the platen bearing 121 of the printing apparatus of this embodiment is described with reference to Figs. 8 and 9. The below-described projecting part 138 is provided in a part of the side surface of the opening/closing arm 130.

The printer apparatus of this embodiment has a structure in which the platen roller 120 can easily detach from the printer apparatus when, for example, a force no less than a predetermined amount is exerted when the printer apparatus is dropped. Accordingly, even if, for example, the printer apparatus is dropped, a large amount of force is not applied to the platen bearing 121 and the like via the opening/closing arm 130 and the like. Thus, a component formed of a mold resin such as the platen bearing 121 can be prevented from being damaged.

Specifically, the contact point 136a between the platen bearing 121 and the lock part 136 of the opening/closing arm 130 is positioned opposite from the side in which the thermal head 110 (heat sink 111) and the first biasing spring 140 are provided with respect to a line L4 illustrated in Fig. 8. Fig. 8 illustrates the line L4 as a chain double-dashed line that connects a center 131a of the arm rotation shaft 131 and the center 121a of the platen bearing 121. That is, the contact point 136a is formed in a position opposite from the direction in which the platen roller 120 is disengaged (illustrated with an arrow C1) with respect to the line L4.

By forming the contact point 136a in a position opposite from the direction in which the platen roller 120 is disengaged (illustrated with the arrow C1 of Fig. 9) with respect to the line L4, a force is exerted to the platen roller 120 in a direction causing the disengagement of the platen roller 120 (illustrated with the arrow C1 of Fig. 9) when, for example, the printer apparatus is dropped. Further, the platen roller 120 can easily disengage because the opening/closing arm 130 can be moved even when the force exerted in the disengaging direction of the platen roller 120 is relatively small.

A case of forming the contact point in a position on the side of the disengaging direction of the platen roller 120 as illustrated with the arrow C1 (i.e. the side in which the thermal head 110 is provided) with respect to the line L4 is described. In this case, a force is exerted to the platen roller 120 in a direction causing the removal of the platen roller 120 as illustrated with the arrow C1. However, because the opening/closing arm 130 cannot be moved unless the force is significantly large, the platen roller 120 cannot disengage. The force that is exerted to the printer apparatus in the direction causing removal of the platen roller 120 is also exerted to the platen bearing 121 of the platen roller 120 via the opening/closing arm 130. Therefore, the platen bearing 121 may be damaged by the exerted force.

With the printer apparatus of this embodiment, the platen roller 120 can easily disengage from the printer apparatus when force is exerted to the platen roller 120 in the direction illustrated with the arrow C1. Therefore, the platen bearing 121 or the like can be prevented from being damaged. That is, in a state of Fig. 10(a), the printer apparatus of this embodiment can easily shift to a state of Fig. 10(b) when force is exerted in the direction C causing removal of the platen roller 120. Thus, the platen roller 120 can easily disengage from the printer apparatus. Accordingly, the platen bearing 121 or the like can be prevented from being damaged.

As illustrated in Fig. 9, the amount of force exerted to the platen roller 120 of the printer apparatus during the removing of the platen roller 120 depends on the size of the angle θ formed by the line L4 and the contact point 136a. Specifically, if the value of the angle θ is small, the platen roller 120 cannot disengage unless a relatively large amount of force is exerted to the printer apparatus. If the value of the angle θ is large, the platen roller 120 can easily disengage even when an amount of force exerted to the printer apparatus is small.

The amount of force required to disengage the platen roller 120 from the printer apparatus may differ depending on the purpose or usage of the printer apparatus. With the printer apparatus of this embodiment, the amount of force required for the platen roller 120 to disengage from the printer apparatus can be adjusted by adjusting the angle θ, that is, the position of the contact point 136a. In the printer apparatus of this embodiment, the contact point 136a is formed to be positioned between the line L3 and the line L4.

In a case where the contact point 136a is positioned between the line L3 and the line L4 as illustrated in Fig. 9, the amount of force that causes the platen roller 120 to disengage from the printer apparatus may be changed due to a slight change in the position of the contact point 136a. That is, even in a case where the printer apparatus is designed to cause the platen roller 120 to disengage from the printer apparatus when a predetermined amount of force is exerted to the printer apparatus, the position of the contact point 136a may deviate from a desired position due to, for example, manufacturing error. Thus, some printer apparatuses may cause the platen roller 120 to disengage from the printer apparatus whereas some printer apparatus may cause the platen roller 120 not disengage from the printer apparatus. Thus, if the platen roller 120 is not disengaged from the printer apparatus even when a large amount of force is exerted to the printer apparatus, the printer apparatus may be damaged when, for example, the printer apparatus is dropped.

Therefore, in this embodiment, the projecting part 138 is provided in the opening/closing arm 130 as illustrated in Figs. 11 and 12.

By allowing the projecting part 138 and the frame 160 to contact each other, the platen bearing 121 and the lock part 136 of the opening/closing arm 130 can contact at a predetermined position which is the contact point 136a.

Accordingly, with the printer apparatus of this embodiment, the platen roller 120 can almost always disengage from the printer apparatus when a substantially constant amount of force is exerted to the printer apparatus. Thereby, the platen bearing 121 or the like can be further prevented from being damaged.

Next, an operation of the opening/closing arm of the printer apparatus according to the embodiment is described with reference to Figs. 13(a)-16(b).

Fig. 13 illustrates the printer apparatus of the embodiment in a state prior to having a lever cap 234 attached thereto. Assuming that the side in which the platen 120 is provided corresponds to the front side, Fig. 13(a) is a perspective view of the printer apparatus observed from the front side, and Fig. 13(b) is a perspective view of the printer apparatus observed from the rear side. Fig. 14 illustrates the printer apparatus of the embodiment in a state having the lever cap 234 attached thereto. Fig. 14(a) is a perspective view of the printer apparatus observed from the front side, and Fig. 14(b) is a perspective view of the printer apparatus observed from the rear side. Fig. 15 illustrates the printer apparatus of the embodiment in a state having a depression button 240 attached thereto. Fig. 15(a) is a perspective view of the printer apparatus observed from the front side, and Fig. 15(b) is a perspective view of the printer apparatus observed from the rear side. Fig. 16(a) illustrates a state where the depression button 240 is not yet pressed, and Fig. 16(b) illustrates a state where the depression button 240 is pressed.

In the printer apparatus of the embodiment, the opening/closing arm cap receiving part 134 is provided in the opening/closing arm 130 as illustrated in Fig. 13. However, in actual use, the lever cap 234 is attached to the opening/closing arm cap receiving part 134 as illustrated in Fig. 14, and the depression button 240 is attached to the lever cap 234 as illustrated in Fig. 15. Accordingly, the opening/closing arm 130 can be operated to move by pressing the depression button 240 interposed by the lever cap 234 and the opening/closing arm cap receiving part 134. That is, the lever cap 234 is lowered from the state illustrated in Fig. 16(a) to the state illustrated in Fig. 16(b) by depressing the depression button 240. Thereby, the opening/closing arm 130 is operated to move about the arm rotation shaft 131.

Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

110

thermal head (printer head)

111

heat sink (head support plate)

120

platen roller

121

platen bearing

121a

center of platen bearing

130

opening/closing arm

131

arm rotation shaft

131a

center of arm rotation shaft

134

opening/closing cap receiving part

135

opening/closing arm opening part

136

lock part

136a

contact part

137

outer contact part

138

projecting part

140

first biasing spring

150

second biasing spring

160

frame

161

frame side surface

162

frame opening part

163

first guide part

163a

edge part

164

second guide part

164a

edge part

170

motor

180

gear part

234

lever cap

240

depression button